Immunization injections are the most common recurring painful medical procedure undertaken in childhood. Numerous evidence-based and feasible interventions are available to mitigate immunization pain, however, there is low uptake of these interventions in clinical practice, revealing a knowledge-to-care gap between what is known about pain and pain management. This is a 4-year single-centre, randomized, parallel 3-group add-on trial that will enrol 3420 mothers hospitalized following the birth of an infant at Mount Sinai Hospital (MSH) in Toronto. The trial will evaluate and compare the impact of two levels of intensity of maternal education about pain management during infant immunizations ('low': pamphlet vs. 'high': pamphlet + video) compared to placebo control after the birth of an infant on maternal behaviour during future infant immunizations at up to 6 months of age (use of analgesic interventions), maternal knowledge and attitudes about pain and pain management up to 6 months after birth.